Electrical winding



June 28, 1932. i

S. E. JOHANNESEN ELECTRICAL WINDING Filed Ma 22, 1950' s m I In Mentor? m o .t me A JG H d w VH s Patented June 28, 1932 I UNITED STATES PATENT OFFICE SVENI) E. JQHANNESEN, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ELECTRICAL WINDING Application filed May 22, 1930. Serial No. 454,812.

My invention relates to electrical windings and has for its object the provision of an improved electrical winding and method of making it.

Although my invention has other applications, it is particularly useful in connection with electrical windings intended to be used in transformers and like electrical apparatus.

It has been found that for small and moderate capacity transformers intended for relatively high voltages, it is preferable to form the transformer with concentric primary and secondary windin s. Insulation, usually in the form of cylin ers, is positioned between these windings so as to insulate the primary from the secondary voltage. It has also been found that it is desirable to use but one primary winding and likewise but one secondary winding for the transformer.

Some difficulty has been experienced when attempting tomake high voltage windings, having the above mentioned desirable characteristic's, with the methods of winding heretofore generally used because the high potential involved required a layer of major lnsulation so thick that a very broad path for leakage flux was created. This generally resulted in a verypoor transformer regulation.

One arrangement was to form the windings with relatively long and shallow primary and secondary windings. In other words, the windings were formed with relatively long and narrow winding spaces. However, with this arrangement it was very difiicult to provide the necessary mechanical and electrical strength, particularly with those high potential windings wherein it was necessary to use a relatively small conductor Wound into a large number of turns per layer, such for example as one hundred or more. It will be appreciated that with such a largenumber of turns per layer, the maximum potential existing between successive layers'may be very great. Thus in the example given, the max1- mum potential between the layers may be the additive voltage of two hundred turns or more. Because of this very high potential difference existing between successiye layers a comparatively large amount of insulation was required between them. Furthermore, it was generally necessary to increase the insulation to a value much in excess of that required between adj ace'nt layers for safe operationbecause of the additive potential existing between a number of layers. Thus, in order to prevent a breakdown between those layers of the windings which are positioned a considerable distance apart it was necessary to provide a considerable amount ofinsulation at the end turns. This of course materially reduced the space factor, and besides tended to separate the adjacent layers to such an extent that the winding was weakened, at times to such an extent that it buckled and became distorted. Therefore, in order to provide the necessary electrical and'mechanical strength it was frequently necessary to use a rather heavy and mechanically strong insulating cylinder between the windings.

In an effort to strengthen these windings mechanicallykso as to permit the use of a.

smaller insulating cylinder, it was proposed to form the high tension windings into single section disc-shaped coils, which in the assembled winding, would be placed side by side along the major insulating cylinder. Here again, however, relatively large voltage steps were encountered, this time between adjacent coil-s rather than between adjacent layers.

Another arrangement was to wind the high tension windings into several back-turn sec tional coils. While this arrangement tended to reduce the electrical stress throughout the winding, it left much to be desired in that the multiple section winding took up a great deal of space and moreover, it was found to be necessary often-times to reduce the insulation to such an extent in order to attain the required efficiency of operation that the windings were not entirely satisfactory when for safe operation.

My invention in one of its aspects contemplates the provision of an electrical winding of greater electrical and mechanical strength,

considered in the light of the requirements one having a very large winding factor commensurate with the available winding space, and one which will operate at a comparative- 1y high efliciency.

s i In carrying my-inventioninto effect in one form thereof, I wind the turns of each layer of the winding so that they are positively interlocked mechanically between the turns of the adjacent layerson both sides. Thetiirns of each layer are spaced so as to receive the turns of the adjacent la ers between them in the spaces rovided. T e interlocking of the turns resu ts in a very strong winding mechanically, and also effects a material increase in the electrical strength of the winding. This results. from the fact that the number of turns per layer is greatly reduced by the spacin and consequently the maximum potential etween adjacent layers also is greatly reduced. This reduction in the electrical stress in the winding, of course, effects a reduction in the amount of'insulation required and thereby increases the winding fac- 'tor materially.

I refer to form the winding with-substantlally parallel convolutions i. e., to form the layers by winding each turn along a circumference of the winding rather than in the form of a helix. In'order to prevent the formation of a lop-sided winding, which would result if the cross-overs from one turn to the next of the turns of successive layers were in the same radial plane, I space the rows of cross-overs of succeeding layers at intervals so as to distribute the cross-over substantially uniformly through the WlIlCl-' ing, and moreover, so that no two of the rows will lie in the same radial plane.

For a more complete understanding of my invention reference should be had to the accompanying drawing in which Fig. 1 is a central longitudinal section of an electrical winding having horizontally wound layers formed in accordance with my invention; Fig.2 is a plan view of an electrical winding similar to that shown in Fig. 1 but having many more turns per layer; .Fig. 3 is a central longitudinal section of an electrical winding of modified form having horizontally wound layers formed in accordance with'my invention; Fi 4 is a central longitudinal section of an ellactrical winding havin layers wound on a bias in accordance wi h m invention; and Fig, 5 is a central longitu inal section of an electrical winding havmg vertically wound layers formed in accordance with my invention.

Referring to the drawing, I have shown In invention in connection with electrical win in particularl useful in transformerapphcations. In ig. 1 I have illustrated an electrical winding having horizontally wound layers. In forming this. winding in accordance with my invention, I have spaced the turns of each layer so that they receive the turns of the adjacent la ers in wedging, interlocking relation where y the coil is strength- I ened both electrically and mechanically. As

shown (Fig. 1), the electrical winding is sulating material such as cotton. The spool 12 may bemade of any suitable material but preferably is moulded frombakelite wood pulp sheets or some like composition. The

winding surface 12a of the spool on which the turns of the first layer "are wound may be roughened so as to assist in holding these turns in place whenwound. Thus, a layer of sand paper 13 may be applied with its roughened abrasive surface outermost so as to engage and I thus assist in holding in place against lateral movement the turns of the first layer of the winding. Such an arrangement for holding the turns of the first layer in place is described and claimed. in the United States patent granted to J. J. Vienneau, No. 1,550,189,

dated August 18, 1925. While the winding surface 12a has been shown to be of cylindrical form it will be understood that it may have other suitable shapes. Thus, the spool may have a square or a polygonal cross-section.

The first layer is formed by winding a number ofturns, for example six, 14, 14a, 14b, 14c, 14d and 14a spaced at intervals on the winding surface 12a from left to right; the second layer is formed by winding a like number of turns 14f--14k from right to left in the spaces formed between the turns of the first layer; the third layer is formed by winding turns'14L-14g in the spaces formed by the turns of the second layer, and so on each of the successivedayers is formed by winding its turns in the spaces between the turns of the next preceding layer. The dashed lines in Fig. 1 indicate the center lines of thelayers. It will be observed by reference to Fig. 1 that the turns 14, late-446 of the first layer are spaced at intervals along the length of the winding surface so that the distance between successive turns is equal to approximately .73

times the diameter of the conductor. This allows the turns of the second layer, and also of each succeeding layer to lie in comparatively wide-spaces so as to be securely anchored between the turns of the preceding layer. It will be observed that when the spaces between adjacent turns equals .73 times the diameter of the conductor, the center lines of'the layers are spaced apart a distance equal to one-half the diameter of the conductor.

This insures a complete interlock between the wound turns.

Preferably, a spacer member 15 formed from some suitable material such as paper twine or an insulated conductor will be positioned between the successive turns of the first layer. As shown, this spacer member is'proportioned so as to lie snugly against the adjacent turns of the first layer, and is shaped as I the turnsof the second layer are wound on so a spacer member at the same time as the conductor is being wound on to form the turns of the first layer. The spaces between the turns of the first layer, however, may be utilized by winding in them an electrical conductor paralle with the turns and permanently secured to the end turns of the layer in some suitable fashion as by soldering. Likewise,

the spaces between the turns of the final layer may be utilized by winding in them an electrical conductor in parallel with the turns, the ends of this conductor also being permanently connected to the end turns of the layer in some suitable'manner, as by soldering.

In order to make a more uniform and'compact winding, I prefer to wind the turns along a circumference as shown in Fig 2 rather than in the form of a helix. In other words, each turn will be wound so that its convolution lies in a plane at right angles to the longitudinal axis of the winding. At the end of each turn the'conductor is shifted into the next succeeding turn and at the end of each layer, the shifting movement is reversed for the next layer. Thus, for each layer a longitudinally extending row of crossovers 16 is formed. It will be understood that if the longitudinally extending cross over rows of the succeeding layers occur substantially in the same radial location, i. e.,

each row builds up over the precedingrow, a

lop-sided winding would result. I prefer to distribute the cross-over rows 16 substantially uniformly by spacing them at substantially equal intervals (Fig. 2) about the windingso. that no two of the rows will be in the same radial line. I am thus enabled to make a very uniform and symmetrical winding. .One means for making my electrical winding automatically with the rows thus spaced is described and claimed in the copending application to L. C. Daniels, Serial No. 373,633, filed Ju-ne'25, 1929.

It will. be observed that by spacing the turns of each layer at intervals equal approximately to .73 times the diameter of the conductor, I reduce the voltage per layer to 58% of the voltage of a layer of the same width wound in the conventional manner, i.e., with the adjacent turns of each layer wound so as to contact with each other. More specifically, I have illustrated in Fig. 1 a winding with five layers of six turns each making a total of thirty turns. The maximum potential in the winding is the additive volts of twelve turns. It will be observed that this maximum potential occurs between the turns of alternate layers which are in contact. Thus, for example, the potential difference between the turn 14 of the first layer and the turn 141 of the third layer is the additive voltage of twelve turns. With the conventional method of winding, above referred to, the winding would be formed with three layersof ten turns each, and the maximum potential between adjacent layers would be the additive volts of nineteen turns.

It is to be noted, however,.that while my winding has five layers for a total of thirty turns to three layers of the conventional winding for the same total number of turns, my winding has a winding depth which ma be either equal to or even less than the win ing depth of the conventional winding. This is due to the fact that the turns wound in accordance with 'my invention are automatically wound much closer by reason of the wedging action between the s aced turns of each layer with those of the ad] acent layers on botlf sides, and also in View of the fact that my winding requires much less insulation from layer to layer because the maximum potential between the layers is greatly reduced. Layer insulation heretofore generally used is usually unnecessary in my winding; In other words, I have provided a very large winding factor commensurate with the available winding space. This elimination of layer insulation also effects an increase in the efiiciency of operation of the winding. Furthermore, the elimination of layer insulation increases greatly the speed of automatic winding. It will be understood that if it be necessary for the operator to insert layer insulation very little time is saved by automatic winding.

Another important feature of my invention is the increased mechanical strength of the winding. It will be observed that each turn of my winding is wedged between the turns of the adjacent layers. It also will be observed that when the turns are s aced at intervals equal to approximately 3 of the diameter of the conductor the center lines of each layer are practically coincident with the tangents common to the adjacent portions of the turns of the adjacent layers on both sides. Thus, the turns are securely anchored in place and are forced to retain the positions they have assumed when wound. Obviously, this feature is very important when the windings are being formed on automatic machines.

I have illustrated in Fig. 3a winding of modified form having layers wound horizontall in accordance with my invention. Each l ayer 21 of this winding, like each layer 11 of Fig. 1, is formed by winding a number of turns 22, 22a, etc., spaced at intervals along the length of the winding surface. It will be observed, however, by reference to Fig. 3 that the spaces between the turns in each layer are slightly less than .73 of the diameter of the conductor. The advantage of this arrangement is that the alternate layers do not touch as is the case in Fig. 1 and consequently the-maximum potential in the modified windin is slightly less than that in the winding of ig. 1. Thus in the modified winding, the potential be is substantially the same'as that shown in Fig. 1. It iseprovided with a winding spool 23 which may have a roughened winding surface 23a. The s acing member 24 is positioned between t e spaced turns of the first layer and is shaped by the turns of the first and second layers as they are ,wound on so as to conform with the curved surfaces of the adjacent turns of the first layer and the bottom curved portions of the turnsof the second layer. The turns of this winding may also be and preferably are wound along a circumference of the winding as are the turns of the windings shown in Figs. 1 and 2. If desired, the fspaces between the turns of the first'and last layers may be utilized by winding in the electrical conductors parallel with the turns of these layers and connected with their end turns.

The electrical windings thus far described, i. e., those windings wherein the layers are wound horizontally, are adapted particularly for moderate voltages'such as 13,000 or less.

For higher voltages, such for example as those ranging between 13,000 and 66,000, I prefer to wind the layers on a bias as shown in Fig. 4, rather than horizontally as shown in Figs. 1 and 3. Referring to Fig. 4, I have shown'an electrical conductor 30 wound in bias layers 31 on a suitable winding spool 32. The winding spool may be provided with a roughened winding surface 3211 so as to assist in holding the turns of the first layer in place against lateral movement. Preferably, the layers will be wound on a bias substantially 30 from the horizontal. One arrangement of winding these layers is asfollows: The 'first turn 33, which forms the first layer, is wound on the winding surface in s aced relation with the inner surface of tiie left hand spool head. The sec.-

ond turn 33a is wound beside it on the winding. surface; however, instead of continuing" on the winding surface, the third turn 33b is laid in the space-between the first turn 33 and the spool head. The second layer is thus formed by the turns 33a and 336. It will be observed that the first turn 33 will have been ispaced such a distance from the left hand spool head that the center line of the second layer will bev on a bias substantially 30 from the horizontal, as is indicated on the drawglhe fourth turn 330 i. e., the first turn of the third layer, is lai in the space formed between thecturns 33a and 33b of the second layer; the next turn 33d is wound on the winding surface beside the turn 33a, thereby completing the third layer. The sixth turn 33e of the ,winding is wound on the winding surface beside the fifth turn 33d, while the seventh turn 33 f is laid in the space between the turns 33a and 33d of the third layer. The last turn 33g of the fourth layer is laid in the gutter between the turns 33b and 330. It will be observed that four layers have been formed on a bias substantially at 30 with the horizontal. The fifth, sixth, and each of the remaining layers of the winding will be wound with their turns laid in the spaces between the turns of the next preceding layer.

It will be observed that each turn wound on is securely anchored in a space provided between turns of the previously wound layer. Therefore, my method of winding bias layers lends itself readily to automatic winding. This is an important advantage over the conventional method of winding bias layers, i. e., themethod wherein the adjacent turns of each layer are wound so as to contact with the conventional method, it has been extremely difficult to hold the wound turns in place.

It will be observed that. the spaces provided between the turns of each layer are equal approximately to .73 of the diameter of the conductor being wound so that the center line of each of the bias layers is substantially coincident with the tangents comeach other. It will be understood that with mon to the adjacent portions of the turns of the layers on both sides. It is to be understood, however, that these spaces may be less than .73 of the diameter of the conductor so that the alternate layers rather than touching as shown in Fig. 4 will be spaced in the manner of the turns of Fig. 3. It is also to be understood that the turns of the bias winding preferably will be wound so that their convolutions lie in planes perpendicular to the axis of the winding. If desired suitable conductors may be wound in the spaces between the turns of the first and last layers in parallel with these turns and permanently connected in any suitable manner with the end turns.

For still higher voltages, it is preferable to wind the layers vertically as shown in Fig. 5. The winding spool 40 in this case is provided with a windin surface 40a, preferably roughened, on t e inner surface of one of the spool heads, as for instancethe left hand head as viewed in Fig. 5. As shown, the

turns 41, 41a and 41b of the first layer are I wound vertically on the roughened winding. surface and are spaced so as to receive the turns 41c and 41d of the second layer between first layer. The turns of the third layer are wound in the spaces provided by the turns of the second layer, and the turns of each of observed that the spaces between the turns of each layer are approximately .73 'of the diameter of the conductor being wound so that here again the center line of each layer is p substantially coincident with the tangents common to the adjacent portions of the turns of the layers on both sides. It is to be understood, however, that the spacing between the turns may be less so that the turns of the alternate layers will be spaced, asiare the turns of the winding shown in Fig. 3, whereby the potential between the layers of the winding is reduced. Preferably, the turns of this winding also will be wound with their convolutions lying in planes perpendicular to the i axis of the winding. Here again, thespaees between the turns of the first and last layers may be utilized by winding in them conductors parallel with the turns and connected permanently with the end turns.

It is to be noted that I am enabled by my method of winding to provide relatively long and shallow electrical windings which are sufiiciently strong mechanically to sustain themselves without the application of relatively large amounts of insulation; the mechanical interlock between the turns provides a very-strong winding, while the reduction in voltage from layer to layer effected by the spacing of the turns necessitates the use of but a relatively small amount'of insulation.

It also is to be noted that all of the windings Whether they be of the horizontal, vertical or bias type lend themselves readily to automatic winding as well as to winding by hand.

While I have shown several embodiments of my invention, it will be understood, of

- portion of the diameter of said conductor so electrical conductor wound into a plurality -of successive layers, the turns of each layer as to receive the turns of the adjacent layers between them in interlocking relation.

2. An electrical winding comprising an being spaced apart a distance equal to a substantial portion of the diameter of said conductor but not greater than .73 times the diconductor but not greater than .73 times the diameter of said insulated conductor so as to receive the turns of the adjacentlayers between them in mechanical interlocking relation.

4. An electrical winding comprising an in sulated electrical conductor wound into a plurality of layers, the turns of each layer being spaced to receive the turns of the adjacent layers on both sides between them so that the center line of each layer is substantially coincident with the-tangents common to the adjacent adjacent layers. .5. An electrical winding comprising an electrical conductor wound into a plurality of successive layers, the turns of each layer being spaced apart a distance substantially equal to .73 times the-diameter of the conductor. V

6. An electrical winding comprising an insulated electrical conductor wound into a plurality of successive layers, the turns of each layer of said insulated conductor being wound on a circumference and being spaced apart a substantial distance" so as to receive the turns of the adj aeent layers between them in-mechanical interlocking relation.

7. An electrical winding co'mprising an electrical conductor wound into a plurality of successive layers, the turns of each layer beingspaced apart at substantially regular intervals and wedged into interlocking relation with the spaced turns of the adjacent layers on both sides of it, the spacing of said turns being equal to-a distance at leasttas great as the radius of said conductor but not greater than .7 3' times the diameter of the conductor whereby the turns of said adjacent layers are in close proximity.

8. An electrical winding comprising an portions of the turns of the electrical conductor wound into a plurality of layers, the turns of each layer being wound on a circumference so that their convolutions 1 lie in planes at right angles to the longitudinal axis of the winding and parallel to each other, said turns also being spaced to receive the turns of the adjacent layers on both sides between them so that the center line of each' layer is substantially coincident with the tangents common to the adjacent portions of the turns of the adjacent layers.

9. The method of winding an electrical conductor to form a coil having superposed layers which consists inwinding said conductor into a layer with the successive turns of each layer spaced aparta distance equal substantially alonga circumference of the layers which consists in-windlng said conductor into a layer with-the successive turns thereof spaced apart a distance-greater than a the radius of said conductor but not greater than .73 times the diameter of the conductor, windin a second layer of turns within the spaces etween the turns of said first layer and so on winding each successive layer of turns in the spaces between the turns of the preceding layer until the desired number of ayers have been wound.

11. The method of winding an electrical conductor to form acoil with superposed layers which consists in winding said conductor on a winding form with the turns wound on the circumferences of said form and spaced apart at regular intervals, the length of the intervals being substantially equal to .73 times the diameter of the conductor, then winding said conductor in the spaces between the turns of the wound layer so as to form a second layer and so on winding each successive layer of turns in the spaces between the turns of the preceding layer until the desired number of layers have been wound,

12. In the winding of coils wherein the turns are wound on a circumference, the method of distributing the cross-overs which consists in bringing the cross-overs of successive layers at different radial portions of the winding;

13. In the winding of coils wherein the turns are wound on a circumference, the method of distributing the cross-overs which consists in crossing over from one turn to the next of each layer so as to form rows of crossovers extending lengthwise of the winding, and spacing the cross-over rows of successive layers at intervals so as to bring them to different radial portions of the winding.

14. In-the winding of coils wherein the turns are wound on a circumference, the method of distributing thecross-overs which consists in crossing over from one turn to the next of each layer in the same radial plane so as to form cross-over rows extending lengthwise of the winding and substantially parallel with its axis, and spacing the cross-' over rows of successive layers at substantially regular intervals so as to bring them to different radial portions of the winding.

15 .,An= electrical winding comprising an electrical conductor wound into a plurality of layers, the turns, of each layer being wound winding so that their convolutions lie in parallel planes positioned substantiallyat right angles to the longitudinal axis of the winding, the cross-overs from one turn to the next in each layer forming a longitudinally extending row and the cross-over rows. of successive layers being spaced at intervals so as to lie in different radial positions in the winding.

16. An electrical winding comprising an electrical conductor wound into a plurality of layers, the turns of each layer being spaced apart, the spaces between said turns being at least as great as the radius of said con.-

ductor but not greater than .73 times the diameter of the conductor, said turns also being wound substantially along a circum-.

ference of the winding so that their convolutions lie in parallel planes positioned sub stantially at right angles to the longitudinal axis of the winding, the cross-overs from one turn to the next in each layer forming a row extending lengthwise of the winding and substantially parallel with its axis, and the cross-over rows of succeeding layers being spaced at substantially regular intervals. so as to bring them to different radial portions of the winding.

- 17.. An electrical winding comprising an electrical conductor wound into a plurality of layers, the turns of each layer being spaced at su stantially regularintervals, the lengths of said intervals being greater than the radius of said conductor but not greater than .73

times the diameter of the conductor whereby said turns are wedged into interlocking relation with the spaced turns of the adj acent' layers on both sides of it, the turns of each layer also being wound substantially along a circumference of the winding so that their convolutions lie in parallel planes positioned substantially at right angles to the longitudinal axis of the winding, the cross-overs from one turn to the next in each layer forming a longitudinally extending row and the cross-over rows of successive layers being spaced at intervals so as to lie in difle'rent,

radial positions in -the winding.

In witness whereof, I have hereunto set my hand this 20th day of May, 1930.

' SVEND E. JOHANNESEN. 

